BAD partly reverses paclitaxel resistance in human ovarian cancer cells

Although paclitaxel is an important chemotherapy agent for the treatment of patients with epithelial ovarian cancer, its utility is significantly limited by the frequent development of drug resistance. Recent evidence suggests that resistance to chemotherapy may be partly related to defects in the apoptotic pathway. In this study we have investigated whether enhancement of apoptotic pathway function through stable expression of the BAD protein is capable of sensitizing human epithelial ovarian cancer cells to the effects of chemotherapy. Expression of HA-BAD in six separate clonal transfectants from two different ovarian cancer cell lines was found to significantly enhance the cytotoxic effects of paclitaxel, vincristine, and, to a lesser extent, etoposide. Enhancement of paclitaxel-induced apoptosis in HA-BAD-expressing clones was demonstrated by trypan blue exclusion, clonogenic cell assay, and flow cytometric evaluation. Importantly, this effect was associated with binding of HA-BAD to BCL-xL and concomitant disruption of BAX:BCL-xL interaction. Taken together, these data suggest that the development of small molecules which mimic the effects of BAD may represent a new class of drugs capable of preventing or reversing resistance to chemotherapy agents such as paclitaxel.     

Induction of broad drug resistance in small cell lung cancer cells and its reversal by paclitaxel

In the pulsed arterial spin labeling (ASL) techniques EPISTAR, PICORE, and FAIR, subtraction of two images in which inflowing blood is first tagged and then not tagged yields a qualitative map of perfusion. An important reason this map is not quantitative is that there is a spatially varying delay in the transit of blood from the tagging region to the imaging slice that cannot be measured from a single subtraction. We introduce here two modifications of pulsed ASL (QUIPSS and QUIPSS II) that avoid this problem by applying additional saturation pulses to control the time duration of the tagged bolus, rendering the technique relatively insensitive to transit delays and improving the quantitation of perfusion.     

紫花牡荆素体外抑制人宫颈癌HeLa细胞增殖的研究

Objective: The aim of the study was to investigate the effect of Casticin on proliferation inhibition of human cervical cancer HeLa cells in vitro and to unravel the associated mechanisms. Methods: Human cervical HeLa cells were cultured in vitro. The inhibitory effect of Casticin on the viability of human cervical cancer HeLa cells was evaluated by the MTT assay.The colony formation ability was detected by plate colony formation assay. Distribution of cell cycle was analyzed by flow cytometry. The protein expression levels were analyzed by Western blot. Results: Casticin significantly inhibited the growth of human cervical cancer HeLa cells in a dose- and time-dependent manner, and the IC50 was 2.82 μg/mL. The colony-forming rate was reduced drastically compared with control group (P ＜ 0.05). The cells were markedly arrested at G2/M phase after the treatment of Casticin for 48 h. Western blot showed that the expression of p21 protein was up-regulated and protein level of Cyclin B1 was depressed by Casticin in a concentration dependent manner. Conclusion: Casticin could inhibit the cell growth and lead to cell arrest in human cervical cancer HeLa cells, and the down-regulation of Cyclin B1 protein expression and activation of p21 protein might contribute to Casticin induced cell arrest in human cervical cancer HeLa cells.     

Proliferation of human non-small-cell lung cancer cell lines: role of interleukin-6

PURPOSE: The aim of this study was to describe the dysmorphogenetic process leading to esophageal atresia and tracheoesophageal fistula (EA + TEF) in the recently developed Adriamycin model of the malformation. METHODS:Time-mated pregnant rats were given either Adriamycin (1.75 mg/kg intraperitoneally) or saline on days 6 to 9 of gestation, and their embryos recovered on days 12, 12.5, and 13 were serially sectioned in the transversal plane and studied microscopically after H&E and PAS staining. The findings were compared with those of age-matched untreated embryos. RESULTS: All untreated and saline embryos were normal, whereas 49% of Adriamycin embryos had foregut malformations. Tracheoesophageal separation was complete on day 12 in control embryos, whereas 9 of 10 Adriamycin-exposed embryos had a common esophagotrachea with low emergence of the bronchi at that stage. This pattern had evolved into that of a regular EA + TEF in all nine malformed embryos by day 13. On day 12.5, esophagotrachea was found in 6 of 13 and EA + TEF in 5 of 13 embryos. Two had less well-defined malformations. CONCLUSIONS: Esophagotrachea equivalent to complete tracheoesophageal cleft is the first step leading to EA + TEF in this model. The full-blown malformation is finally acquired by partial loss of the posterior wall of the foregut, which tapers-off in the mediastinal mesenchyme and respiratory differentiation of the anterior wall down to the level of bronchial bifurcation, where it constitutes the fistula and the distal esophagus.     

Short-course induction chemoradiotherapy with paclitaxel for stage III non-small-cell lung cancer

BACKGROUND: This study assessed toxicity, tumor response, disease control, and survival after short-course induction chemoradiotherapy and surgical resection in patients with stage III non-small-cell lung carcinoma. METHODS: Forty-five patients with stage III non-small-cell lung carcinoma received 12-day induction therapy of a 96-hour continuous infusion of cisplatin (20 mg/m2 per day), 24-hour infusion of paclitaxel (175 mg/m2), and concurrent accelerated fractionation radiation therapy (1.5 Gy twice daily) to a dose of 30 Gy. Surgical resection was scheduled for 4 weeks later. Postoperatively, a second identical course of chemotherapy and concurrent radiation therapy (30 to 33 Gy) was given. RESULTS: Induction toxicity resulted in hospitalization of 18 (40%) patients for neutropenic fever. No induction deaths occurred. Of 40 (89%) patients who underwent thoracotomy, resection for cure was possible in 32 (71%) patients. Pathologic response was noted in 21 (47%) patients, and 14 (31%) were downstaged to mediastinal node negative (stage 0, I, or II). At a median follow-up of 19 months, 24 patients were alive, 10 with recurrent disease. Of 21 deaths, 16 were from recurrent disease, three were from treatment, and two were unrelated. Recurrent disease was distant in 21 patients, distant and locoregional in 2, and locoregional in 3. The Kaplan-Meier projected 24-month survival is 49%. Projected 24-month survival is 61% for stage IIIA, 17% for stage IIIB (p = 0.035); 84% for pathologic responders, 22% for nonresponders (p<0.001); 83% for downstaged patients (stage 0, I, or II), 33% for those not downstaged (p = 0.005); and 63% for resectable patients, 14% for unresectable patients (p = 0.007). CONCLUSIONS: We conclude that short-course neoadjuvant therapy with paclitaxel (1) has manageable toxicity and a low treatment mortality, (2) results in good tumor response and downstaging, (3) provides excellent locoregional control with most recurrences being distant, and (4) has improved the median survival compared with historical controls. Survival was better in stage IIIA patients, resectable patients, pathologic responders, and patients downstaged to mediastinal node negative disease (stage 0, I, or II).     

Potentiation of paclitaxel cytotoxicity by inostamycin in human small cell lung carcinoma, Ms-1 cells

A robust new analytical method has been developed for the determination of 5-fluorouracil (5-FU) in human plasma samples using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The method is based on a liquid-liquid extraction procedure, precolumn derivatization, reversed-phase HPLC separation, and detection using atmospheric pressure chemical ionization and selected reaction monitoring. The derivatization agent used was 4-bromomethyl-7-methoxycoumarin. The internal standard for the assay procedure was a stable isotope labeled analog of 5-FU. The lower limit of quantitation was 1.0 ng/mL using 500 microL aliquots of plasma. Sample throughput on the mass spectrometer was approximately 17 samples/h (3.5 min/sample). The method was fully validated. The recovery of 5-FU averaged 76.1%. The accuracy of the assay, assessed from quality control samples, ranged from 99.1% to 104.3% (% theoretical). The overall interassay precision (% RSD) was 2.7%, and the intraassay precision (% RSD) ranged from 1.5% to 3.9%. The derivatized samples were found to be stable under sample analysis conditions and during refrigerator storage. The method was specific for the determination of 5-FU.     

A phase II study of paclitaxel in heavily pretreated patients with small-cell lung cancer

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are major complications associated with total knee arthroplasty. The American College of Chest Physicians recommends twice-daily, fixed-dose low-molecular-weight heparin (LMWH) as routine prophylaxis in this patient population. This study represents a cost analysis of ardeparin and enoxaparin, the two LMWHs currently available for this indication in the United States. Costs for treating DVT, PE, and major bleeding episodes were derived from values reported in the literature. Both ardeparin and enoxaparin were found to produce significant cost savings when used routinely as DVT prophylaxis after knee replacement surgery compared with no prophylaxis. Based on the currently available data, enoxaparin 40 mg once daily appears to be the least costly LMWH for routine pharmacoprophylaxis of DVT in patients undergoing knee replacement surgery.     

A case of advanced vulvar cancer treated with combination therapy

Presented is a patient with advanced vulvar cancer involving the vagina, the perineum and the anus, with metastases to inguinal lymph nodes. The patient received irradiation and next, an artificial sigmoidal anus was made, with simultaneous vulvectomy performed with an electrosurgery. The patient's survival of 3 years and 3 months encourages to consider in such cases an attempt at applying aggressive surgical treatment combined with external radiotherapy.     

The clinical development of paclitaxel and the paclitaxel/carboplatin combination

A randomized controlled trial was designed to investigate the therapeutic benefit of a combination chemotherapy consisting of MTX, 5-FU and THP in patients with advanced or recurrent gastric carcinoma. The patients were randomized into two groups; Group A patients (n = 37) underwent our combined chemotherapy, whereas Group B (n = 34) underwent chemotherapy with 5-FU alone as a control. There were no significant differences in various background factors between the groups. The median survival time was roughly 170 days after the randomization for the patients with advanced cancer (n = 26 for Group A and n = 25 for Group B), with no significant difference between the groups. Two long survivors, however, belonged to Group A. The median survival time of 161 days for Group A (n = 11) was longer than that of Group B (84 days, n = 9), but the difference was not statistically significant. The incidence of toxicities (leukopenia in particular) exceeding JCOG grade 3 was significantly higher for Group A, but no morbidity was observed. These results imply that patients with advanced or recurrent gastric carcinoma may benefit from a regimen of MTX, 5-FU and THP.     

Successful pregnancy after conditioning with cyclophosphamide and fractionated total body irradiation

We report the case of a 24-year-old man who received high-dose cyclophosphamide (CY) 120 mg/kg over 2 days and twice daily fractionated total body irradiation (TBI) over 3 days(1,320 cGy) prior to allogeneic bone marrow transplantation. Seven and one-half years later he fathered a normal child who has developed normally so far.     

Long-term survival results for patients with locally advanced, initially unresectable non-small cell lung cancer treated with aggressive concurrent chemoradiation

The present study was performed to investigate whether modes of voluntary contraction have an influence on an appearance of the premovement silent period (PSP) and components of the premovement cortical potentials. The EMG and the EEG were simultaneously recorded in an isometric ballistic contraction for exerting rapidly an elbow extension force and in a ballistic contraction for fast extending an elbow joint. The prime mover in the 2 contraction modes was the triceps brachii muscle. The frequency of the PSP was significantly higher in the isometric ballistic contraction than in the ballistic contraction (P < 0.01). The duration of the PSP was significantly longer in the isometric ballistic contraction than in the ballistic contraction (P < 0.01). In the isometric ballistic contraction, the 3 premovement cortical potentials (FNP, SNP and TNP) were identified. However, in the ballistic contraction the TNP did not appear. The PSP occurred in the phase of the TNP. The results obtained suggest that the PSP and the TNP are related to a more forceful contraction with faster rates of contraction, rather than only to speed of muscular contraction.     

Second lung cancers in patients successfully treated for lung cancer

The rate of developing second lung cancers and other aerodigestive tumors in patients who have been treated for both small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) is approximately 10-fold higher than other adult smokers. The risk of second lung cancers in patients surviving resection of NSCLC is approximately 1% to 2% per year. The series reported show that the patients who develop second NSCLCs tend to have early-stage NSCLC (predominantly stage I and II). The survival of patients after the second resection of lung cancer is similar to that of patients presenting with initial NSCLC. The risk of second lung cancers in patients surviving SCLC is 2% to 14% per patient per year and increases two- to seven-fold with the passage of time from 2 to 10 years. The risk of second lung cancers in patients treated for SCLC appears to be higher than that found in patients with NSCLC who were treated only with surgical resection. In addition, the chances of successful resection of second primary NSCLCs in patients who were treated for SCLC is much less than that for patients with metachronous lung cancers after an initial NSCLC. Patients treated for SCLC who continue to smoke cigarettes increase their rate of developing second lung cancers. The contribution of chest radiation and chemotherapy administration to the risk of developing second lung tumors remain to be defined but may be responsible for some of the increased risk in patients treated for SCLC compared to patients undergoing a surgical resection for NSCLC.     

Efficacy and safety of prophylactic cranial irradiation in patients with small cell lung cancer

In this review we examine the complex interactions between lipoprotein metabolism, immunosuppressive drug therapy, and inflammation and the potential benefits of lipid-lowering drug therapy after heart transplantation. The newer formulations of cyclosporine, Neoral (Novartis Pharmaceuticals; Basle, Switzerland), and other newer agents such as tacrolimus may have advantages in regard to lipid metabolism as compared with traditional triple-drug immunosuppression. Lipoprotein levels may influence both the toxicity and efficacy of cyclosporine. Dyslipidemia may adversely influence inflammation and rejection in the allograft. Two recent clinical trials have shown that lipid-lowering therapy with a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor alone or in combination with low-density lipoprotein apheresis may confer significant benefits toward preventing transplant coronary artery disease.     

Determinants of CPT-11 and SN-38 activities in human lung cancer cells

Irinotecan (CPT-11) is a semisynthetic camptothecin derivative with a broad spectrum of anti-tumour activity. Carboxylesterase (CE) catalyses the conversion of CPT-11 to SN-38 (7-ethyl-10-hydroxycamptothecin), the active form of CPT-11. The antiproliferative effects of CPT-11 and SN-38, CE-activity and topoisomerase I protein expression were investigated in five human small-cell lung cancer (SCLC) cell lines and four human non-small-cell lung cancer (NSCLC) cell lines. Antiproliferative activity, expressed as IC50 values, was determined using the MTT assay. CPT-11 was significantly more active in SCLC than in NSCLC cell lines (P = 0.0036), whereas no significant difference between histological types was observed with SN-38. A significant correlation (r2 = 0.52, P = 0.028) was observed between CE activity and chemosensitivity to CPT-11 but not to SN-38, and significantly higher CE activity was observed in SCLC compared with NSCLC cell lines (P = 0.025). Western blotting experiments showed topoisomerase I protein expressions within a factor of 2, and a granular nuclear staining was detectable in all cell lines by immunocytochemistry of cytospins. No correlation was observed between protein expression and sensitivity to CPT-11 or SN-38. Cellular and medium concentrations of CPT-11 and SN-38 were measured by high-performance liquid chromatography (HPLC) in one SCLC cell line with high CE activity and high sensitivity to CPT-11, and one NSCLC cell line with low sensitivity to CPT-11 and CE activity. Intracellular concentrations of CPT-11 and SN-38 were higher in the SCLC cell line, and this was associated with an increase in cellular uptake of CPT-11 compared with the medium, and an increased intracellular formation of SN-38. In conclusion, CE activity appears to be associated with higher sensitivity to CPT-11 in human lung cancer cell lines and may partly explain the difference in the in vitro sensitivity to CPT-11 between SCLC and NSCLC cells. The assessment of CE activity in clinical material of lung cancer patients undergoing treatment with CPT-11 may be warranted. However, other mechanisms may influence sensitivity to CPT-11, possibly including drug transport.     

Radiotherapy, local control and survival in lung cancer

Better local control in locally advanced IIIA-B non small cell lung cancer, not considered for surgery, can be achieved through therapy intensification with non conventional fractionation of radiation dose, concomitant boost to the tumor volume, conformal therapy and combined modality therapy. All these procedures tend to produce an improved response, which, if stable in time, may also improve local control and survival. The reported experiences define a positive and encouraging trend on which new guidelines for a more suitable definition of standard therapies for the disease can be modulated.     

5-Fluorouracil interferes with paclitaxel cytotoxicity against human solid tumor cells

Paclitaxel, a naturally occurring antimitotic agent, has shown efficacy in the treatment of certain solid tumors, particularly metastatic breast carcinoma and drug-refractory ovarian cancers. Recent studies have demonstrated that paclitaxel, in addition to its effects on microtubules and cell cycle arrest, possesses significant cell-killing activity in solid tumor cells by the induction of apoptosis. However, the mechanism by which paclitaxel leads to cell death and its relationship with paclitaxel-induced mitotic arrest is presently unclear. In this study, we attempted to determine whether pre-arresting tumor cells at other phases of the cell cycle could affect paclitaxel-induced apoptosis. We found that 5-fluorouracil (5-FU), another antineoplastic agent that usually arrests tumor cells at the G1-S phase of the cell cycle, could significantly repress the cell-killing activity of paclitaxel in solid tumor cells, even when it was added simultaneously with paclitaxel. Further studies indicated that 5-FU actually inhibits the cytotoxic effects of paclitaxel on both mitotic arrest and apoptotic cell death, suggesting that 5-FU might interfere with paclitaxel cytotoxicity at an early stage, probably by preventing tumor cells from entering G2-M phase. Because recent clinical trials have used a combination of paclitaxel and 5-FU in the treatment of metastatic breast cancers, our results also suggest that the combination of these two drugs might not be as valuable in clinical chemotherapy.     

Influence of locoregional irradiation on local control and survival in breast cancer

A profiling ELISA was developed to detect antibody to the non-structural (NS) proteins Lb, 2C, 3A, 3D, and the polyprotein 3ABC, of foot-and-mouth disease virus (FMDV). The assay was used to examine panels of sera from naive cattle, and from experimentally infected or vaccinated animals. All sera from cattle experimentally infected with any of the seven serotypes of FMDV were positive for antibody to 2C, 3A, 3D and 3ABC, and the majority were positive for Lb. The three categories of sera could be differentiated on the basis of the presence or absence of antibody to the structural and/or NS proteins of FMDV. The assay is simple, rapid and reproducible and can be used to identify previous infection in animals which are seropositive for antibody to the structural proteins of the virus. Validating the assay with field sera demonstrated that antibody to 3ABC, and usually one or more of the other non-structural proteins, was detected only in animals reported to have shown clinical signs of FMD. Vaccinated cattle which had received less than five vaccinations, were frequently positive for antibody to 3D but were negative for antibody to 3ABC. Occasional animals which had received more than ten vaccinations had NS protein antibody profiles which were similar to those seen following infection.     

Synergistic inhibition of growth and induction of apoptosis by 8-chloro-cAMP and paclitaxel or cisplatin in human cancer cells

8-Chloro-cAMP (8-Cl-cAMP) is a novel agent that is able to inhibit the growth of a wide variety of cancer cell types in vitro and in vivo and, at doses devoid of toxicity, to achieve plasma concentrations in cancer patients in a range effective for cancer cell growth inhibition. In this study, we have demonstrated that 8-Cl-cAMP, at a dose causing mild or no growth inhibition, synergistically increased the growth-inhibitory effect of paclitaxel or cisplatin in a wide series of cell lines including human breast, lung, ovary, colon, and head carcinomas and melanoma. A similar effect was also observed with another taxane, docetaxel, and with the platinum-derivative carboplatin. 8-Cl-cAMP also markedly enhanced apoptotic cell death induced by each cytotoxic drug. A cooperative antitumor effect was also observed in vivo, because treatment with paclitaxel followed by 8-Cl-cAMP markedly inhibited the growth of GEO human colon cancer xenografts as compared to paclitaxel alone without signs of toxicity. These data demonstrate that 8-Cl-cAMP synergistically increases the antiproliferative activity of taxanes and platinum-derived compounds and provide a rationale to use 8-Cl-cAMP in combination with taxanes and platinum-derived compounds.     

Relationships between cell density, glutathione and proliferation of A549 human lung adenocarcinoma cells treated with acrolein

Acrolein is a highly electrophilic alpha,beta-unsaturated aldehyde to which humans are exposed in various situations. Acrolein reacts rapidly with and depletes cellular glutathione (GSH), and is toxic to various types of cells. In the current study, the ability of acrolein to alter proliferation of A549 cells was found to be dependent on cell density as well as total cell number. Thus, 'doses' must be expressed per cell rather than as a concentration, and all related studies need to be performed by plating a constant number of cells. A549 cells were plated at various densities and treated with acrolein after 48 h. Acrolein doses up to 47 fmol/cell at the time of treatment did not cause cell lethality. However, growth of A549 cells (as shown by thymidine incorporation, alamarBlue and total protein) was inhibited at acrolein levels > 34 fmol/cell in 6-well plates seeded at 5000 cells/cm2 48 h prior to treatment. Cellular GSH levels were decreased 34% by 2 h at acrolein levels of 6.7 fmol/cell and by 65% at 47 fmol/cell. Recovery of GSH was rapid at 6.7-47 fmol/cell acrolein, returning to control levels or above by 12 h post-treatment. These data show a strong correlation between cellular GSH and proliferation. The apparent conflict with a previous study of Ramu et al., suggesting that sublethal concentrations (up to 10 microM) of acrolein inhibited the proliferation of A549 cells without a decline in total cellular GSH, arose because, while the acrolein concentration was the same in cells used for proliferation and GSH assays, GSH measurements were done in cells plated at a higher density, resulting in a much lower acrolein dose per cell. Interestingly, very low dose levels of acrolein with cells seeded at low densities stimulated cell growth despite an initial decline in GSH content. Preliminary studies with the stress genes hsp70 and gadd153 suggest that acrolein at 35 fmol/cell does not stimulate formation of their mRNA beyond the level stimulated by a 2 h incubation in serum-free medium but may actually delay or decrease the induced expression. The mechanism(s) of the inhibitory and mitogenic effects of acrolein remains to be determined, but could be due to changes in gene expression induced by this electrophile, perhaps mediated by changes in GSH.